In the past, the so-called non-prism measuring instrument has been known, in which a pulsed laser beam is projected for scanning an object to be measured and a distance measurement is performed based on a light reflected from the object to be measured, and three-dimensional measurement is performed on the object to be measured based on the value of the measured distance thus obtained and based on an elevation angle and a horizontal angle at a measuring point. In recent years, there has been a three-dimensional measuring instrument called a laser scanner in which measurement on a multiple of points can be performed at high speed.
The non-prism measuring instrument can perform measurement for long distance with high measurement accuracy and can measure reliably on the object to be measured. However, the measurement is performed by manual operation for each point, and much time is required to measure a multiple of points on rock, face of slope, etc. and to acquire planar data. Also, measurement operators need to check each time for omission or duplication of measurement at the measuring site. In order for the control, it has been practiced to obtain hard copies of an image of the object to be measured taken by a digital camera or the like and to put marks on the measured positions during observation.
In the measurement using the laser scanner, detailed and planar three-dimensional data of the object to be measured can be acquired within short time. However, in normal cases, the final results needed in the fields of the operation of measurement in civil engineering or instrumentation are drawings, and only the data of specific portions such as a corner, a contour, etc. of the object to be measured are needed. Therefore, in the data processing after measurement, in order to extract the measurement data of the portions needed for the preparation of drawings from vast amount of point group data, there are such problems that much time is required and it is necessary to record and control a large amount of data. Further, most of the laser scanners can carry out measurement for only up to several hundreds of meters. The measurement for long distance is difficult to carry out, and also, there are such problems that noise or point density during the scanning are not uniform.
Under the above circumstances, it is an object of the present invention to provide a surveying device, by which it is possible to perform measurement on a multiple of points with high accuracy and with high efficiency, and to simply and easily perform data processing and control after the measurement.